This invention relates to winch cables, and more particularly, a device for maintaining the tension on lift cables to prevent cable entanglement.
In lifting devices, such as boatlifts, a lift cable is wound around a drum which is being rotated by a self-locking gear reduction unit. Thus, the drum effectively becomes a winch spool. Ideally, the cable should wind around the drum evenly without crossing or tangling, which can only be accomplished by maintaining cable tension. The proper winding of the cables is very important for two primary reasons: 1) cross or tangled cables significantly shorten cable life and 2) cross or tangled cables may cut themselves, thereby dropping the load. Thus, it is necessary to maintain tension on the cables.
Typically there are two different cable routes used in the boatlift industry: single part line and two part line. Single part line has a weight, or tensioner, which can be affixed to the cable above the lower members, thus maintaining tension when the lower members are resting on a fixed point or when effectively lightened by bouancy or wave action. However, two part line cannot use the tensioner as described above because the cable runs through a pulley on the lower members. Thus, cabling problems remain a constant problem in the boatlift industry when using two part cables.
Currently, there are two ways to solve this problem: 1) by using cable keepers and 2) by using weighted snatch blocks. Cable keepers consist of a means of applying tension against the cable and the winder bar. A significant drawback to using this product is that if the boatlift is allowed to run once the weight is off the cable, the cable tends to protrude away from the winder. When the lift is restarted, however, the loop of cable which was formed tends to get caught under the cable keeper, often causing serious damage to the boatlift and the boat.
On the other hand, weighted snatch blocks move the pulley in the lower member to a weighted “Snatch Block” attached to the lower member by means of a cable or chain. Although the weighted snatch blocks will maintain proper cable tension, the overall length of the device and its attachments severely limits the height the boat can be raised to, making the device extremely undesirable to many boaters.
Thus, the present invention will prevent the crossing and tangling of cables by maintaining proper cable tension. In addition, the present invention will not limit the height to which the boat can be raised.
The prior art includes the following United States patents:
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